We will subject plasma to stagnation point and other flow patterns, on glass and non-wettable surfaces as well as over patterns of non-wettable on wettable surfaces, and then study platelet and granulocyte adhesion in stagnant blood to the resulting surfaces. Antisera will be used to identify the proteins deposited and/or modified by the human plasma under influence of flow. Also, another spiral flow chamber will be made, similar to the one we use now, having a lxl mm spiral groove with loops spaced 1 mm apart, but its diameter will be about twice the original so that its path length over a 3x3 inch area will be about 1.5 m. Probably, plasma replaces the fibrinogen it deposits on glass, by high molecular weight kininogen; if so, activation of plasma during its long flow over glass will cause it to leave fibrinogen deposited latest to remain adsorbed the longest, and subsequently this area will allow platelets suspended in serum to adhere.